The Cannonball Alley was an obstacle, that appeared on American Ninja Warrior 6 during Venice Beach finals, as well as American Ninja Warrior 7 during Orlando finals. It was known for being one of the most difficult obstacle in American Ninja Warrior history.
American Ninja Warrior 6
On American Ninja Warrior 6, Cannonball Alley appeared as the eighth obstacle in Venice Beach finals. It consisted of three different sized balls, increasing in size on a slight decline, swinging back and forth from two secured lines. 14 competitors attempted the obstacle with different strategies, but none were successful, gaining a 100% failure rate for most of the night. It was finally conquered by Kevin Bull, who wrapped his legs around the third cannonball and swung upside down towards the landing mat, eventually becoming the first finisher. 16 competitors who made it there failed, including top competitors such as Derek Nakamoto, Evan Dollard, Kyle Cochran, and Alan Connealy. A total of 20 people attempted it. Only three others could completed, Dustin Rocho and James McGrath (who both failed the next obstacle, the Body Prop), and David Campbell, who was the last runner and managed to become the second finisher.
American Ninja Warrior 7
Cannonball Alley appeared once again on American Ninja Warrior 7 during Orlando finals. Just like in the previous season, it had been the top killer of the majority of the competitors, eliminating veterans like Jo Jo Bynum and Jared Woods and was able to eliminate 10 competitors total. A total of 18 competitors reached Cannonball Alley, giving it a 54% success rate for most of the competitors. Eight competitors could get past this obstacle, including Flip Rodriguez, Travis Rosen, Drew Drechsel, and James McGrath (who completed this obstacle during American Ninja Warrior 6's Venice Beach finals).
On American Ninja Warrior 6's Las Vegas finals, a modified version of Cannonball Alley appeared as the first obstacle in Stage Three, replacing the Roulette Cylinder. Unlike the Cannonball Alley, the balls were ascending, with the largest ball in the middle, and secured by one chain. This left the smaller sized balls to swing in any direction. It eliminated no one out of the two competitors who attempted it (both Joe Moravsky and Elet Hall could get pass it). However, on USA vs. The World, the balls were enlarged to the same size as the Cannonball Alley. As the result, it eliminated Paul Kasemir and Asa Kazuma. No one else failed it, since they either maintained grip and momentum, or skipped the middle ball altogether. It was replaced by the Psycho Chainsaw on American Ninja Warrior 7.